In a high-stakes corruption case, ICAC Principal Investigator Kong Kin-chau edges closer to the truth within a listed company. Chief Investigator Szeto Kai-man and Assistant Investigator Ting Sum go undercover as a father-daughter duo to gather evidence against a construction firm, while Firearms Team member Chui Ho-nam and Assistant Investigator Chung Hau-ling help secure crucial intel. Meanwhile, Senior Investigator Ng Hok-bun exposes corruption within the prison system. Despite differing views and setbacks, the team remains steadfast in pursuing justice in the secondary school engineering scandal.